The present invention relates to 1-phenyl-3-dimethylaminopropane compounds, to a method of preparing them, and to the use of these substances as pharmaceutical active ingredients.
The treatment of chronic and non-chronic pain situations is of great importance in medicine. This is reflected in the large number of publications. Thus, for example, 1-naphthyl-3-aminopropane-1-ols with an analgesic-narcotic effect are known from EP 176 049. Secondary and tertiary alcohols with .gamma.-amino groups are described in J. Pharm. Sci. 59, 1038 (1970) and in J. Prakt. Chem. 323, 793 (1981); phenyl-dimethylaminopropanols containing a para-substituted phenyl radical are described in Chem. Abstr. 54, 20963c (1960) and in Chem. Abstr. 63, 6912e (1965). These compounds also possess analgesic properties. In contrast, the 3-dimethylaminopropan-1-ols containing 2-phenyl radicals described in DE 32 42 922 have an antidepressant effect. The 1-phenyl-propan-1-ols described in J. Pharm. Sci. 57, 1487 (1968) have different pharmacological effects depending on the .gamma.-aza ring.
Opioids have been used for many years as analgesics for the treatment of pain, although they give rise to a series of side effects, for example addiction and dependency, respiratory depression, gastrointestinal inhibition and obstipation. They can therefore only be given over an extended period of time or in higher doses subject to special precautionary measures such as special prescription regulations (Goodman, Gilman in "The Pharmacological Basis of Therapeutics", Pergamon Press, New York (1990)).
Tramadol hydrochloride--(1RS,2RS)-2-[(dimethylamino)methyl]-1-(3-methoxyphenyl)cycl ohexanol hydrochloride--assumes a special position amongst centrally-acting analgesics, since this active ingredient gives rise to a pronounced inhibition of pain without the side effects which are known for opioids (J. Pharmacol. Exptl. Ther.4 267, 331 (1993)). Tramadol is a racemate and consists of identical amounts of (+) and (-) enantiomer. In vivo the active ingredient forms the metabolite O-desmethyl-tramadol, which is likewise present as a mixture of enantiomers. Investigations have shown that both the enantiomers of tramadol and the enantiomers of tramadol metabolites contribute to the analgesic effect (J. Pharmacol. Exp. Ther. 260, 275 (1992)).